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D.Man Hazarika
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Homework Statement
A body is dropped from certain height H. If the ratio of the distances traveled by it in (n-3) seconds to (n-3)rd second is 4:3, find H (take g= 10 m/s²) (answer: 125m)
Homework Equations
The Attempt at a Solution
I did this way but I came to a dead end...
To find H,
s= 1/2 gt²
= 1/2 * 10 * (n-3)²
= 5*(n²-9)
= 5n²+45...(I)
S nth = u+g/2(2n-1)
= 5(2n-1)
= 10n-5...(II)
equating (I) AND (2)
5n²+45= 4
________ ___
10n-5. 3
=> 3(5n²+45)=4(10n-5)
=> 15n²+135=40n-20
=> 15n²-40n=-20-135
=> 15n²-40n=-155
=> 15n²+155=40n
=> 15n²+155= 40
____________
n
This is a dead end...what should I do next...?